Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute what are joseph's average speed and velocities in jogging (a) from A to B and (b) from A to C.

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Chapter 7

NCERT

Class 9

Science

Solutions

2. Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute what are joseph's average speed and velocities in jogging

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Question:

Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute what are joseph's average speed and velocities in jogging (a) from A to B and (b) from A to C.

Answer:

From point A to B

Distance covered= 300m

Displacement= 300m

Time taken= 2 min 30 sec

= (2 * 60) + 30 = 150sec

Average speed= Distance covered/ Time taken

= 300/150 =2m/sec

Average velocity= Displacement/ Time Taken

= 300/150 = 2m/sec

From point A to C

Distance covered= 300 + 100 = 400m

Displacement= 300 - 100 = 200m

Time taken= 3 min 30 sec = (3 * 60) +30 = 210 sec

Average speed= Distance covered/ Time taken

=400/210 =1.90m/ sec

Average velocity= Displacement/ Time Taken

= 200/210

= 0.95 m/sec.

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